A Medical Student-Run Telehealth Primary Care Clinic During the COVID-19 Pandemic: Maintaining Care for the Underserved.

BACKGROUND: In this report, we outline our approach to implementing a hybrid in-person and virtual clinic model at a student-run free clinic (SRFC) during the COVID-19 pandemic. Individuals of low socioeconomic status (SES) are at an increased risk for COVID-19 infection and severe clinical outcomes. It is unclear if telehealth is a viable continuity of care enabler for the underserved. METHODS: The Weill Cornell Community Clinic (WCCC) implemented a novel telehealth clinic model to serve uninsured patients in May 2020. A phone survey of was conducted to assess WCCC patients access to technology needed for telehealth visits (eg, personal computers, smartphones). Patient no-show rates were retrospectively assessed for both in-person (pre-pandemic) and hybrid continuity of care models. RESULTS: The phone survey found that 90% of WCCC patients had access to technology needed for telehealth visits. In the 8 months following implementation of the hybrid model, telehealth and in-person no-show rates were 11% (14/128) and 15% (10/67) respectively; the combined hybrid no-show rate was 12% (24/195). For comparison, the in-person 2019 no-show rate was 23% (84/367). This study aligns with previous reports that telehealth improves patient attendance. CONCLUSION: Literature on the transition of SRFCs from in-person to telehealth care delivery models is limited. At the WCCC, the reduction in no-show rates supports the feasibility and benefits of adopting telehealth for the delivery of care to underserved patient populations. We believe the hybrid telehealth model described here is a viable model for other student run free clinics to increase access to care in low SES communities.

Stem cells expand potency and alter tissue fitness by accumulating diverse epigenetic memories.

Immune and tissue stem cells retain an epigenetic memory of inflammation that intensifies sensitivity to future encounters. We investigated whether and to what consequence stem cells possess and accumulate memories of diverse experiences. Monitoring a choreographed response to wounds, we found that as hair follicle stem cells leave their niche, migrate to repair damaged epidermis, and take up long-term foreign residence there, they accumulate long-lasting epigenetic memories of each experience, culminating in post-repair epigenetic adaptations that sustain the epidermal transcriptional program and surface barrier. Each memory is distinct, separable, and has its own physiological impact, collectively endowing these stem cells with heightened regenerative ability to heal wounds and broadening their tissue-regenerating tasks relative to their naïve counterparts.

Dietary interventions as regulators of stem cell behavior in homeostasis and disease.

Stem cells maintain tissues by balancing self-renewal with differentiation. A stem cell's local microenvironment, or niche, informs stem cell behavior and receives inputs at multiple levels. Increasingly, it is becoming clear that the overall metabolic status of an organism or metabolites themselves can function as integral members of the niche to alter stem cell fate. Macroscopic dietary interventions such as caloric restriction, the ketogenic diet, and a high-fat diet systemically alter an organism's metabolic state in different ways. Intriguingly, however, they all converge on a propensity to enhance self-renewal. Here, we highlight our current knowledge on how dietary changes feed into stem cell behavior across a wide variety of tissues and illuminate possible explanations for why diverse interventions can result in similar stem cell phenotypes. In so doing, we hope to inspire new avenues of inquiry into the importance of metabolism in stem cell homeostasis and disease.

Author Correction: Extracellular serine controls epidermal stem cell fate and tumour initiation.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Extracellular serine controls epidermal stem cell fate and tumour initiation.

Tissue stem cells are the cell of origin for many malignancies. Metabolites regulate the balance between self-renewal and differentiation, but whether endogenous metabolic pathways or nutrient availability predispose stem cells towards transformation remains unknown. Here, we address this question in epidermal stem cells (EpdSCs), which are a cell of origin for squamous cell carcinoma. We find that oncogenic EpdSCs are serine auxotrophs whose growth and self-renewal require abundant exogenous serine. When extracellular serine is limited, EpdSCs activate de novo serine synthesis, which in turn stimulates α-ketoglutarate-dependent dioxygenases that remove the repressive histone modification H3K27me3 and activate differentiation programmes. Accordingly, serine starvation or enforced α-ketoglutarate production antagonizes squamous cell carcinoma growth. Conversely, blocking serine synthesis or repressing α-ketoglutarate-driven demethylation facilitates malignant progression. Together, these findings reveal that extracellular serine is a critical determinant of EpdSC fate and provide insight into how nutrient availability is integrated with stem cell fate decisions during tumour initiation.